DETROIT (CNNMoney.com) -- Ford wants to roll out a fleet of hybrid and plug-in cars over the next several years, but it does not want to go down the road General Motors is taking with the Chevrolet Volt.

The Volt, which is expected to go on sale late next year, will use purely electric power to drive the wheels, and a gasoline engine will only be used to generate electricity for longer range. But Ford engineers believe that using a gas engine that way won't deliver both the fuel economy and performance customers want.

Instead, Ford wants to build fully electric vehicles - with no gas engine at all - as well as advanced hybrids, including plug-in hybrids, where the gas engine drives the wheels directly. Ford believes vehicles like these will better meet real-world needs.

"We just felt that regular hybrids, along with plug-in hybrids and full electric were just better alternatives for our customers," said Barb Samardzich, Ford's vice president for global powertrain engineering in an interview at the Detroit Auto Show.

Customers who want all-electric drive can simply buy one of Ford's upcoming electric vehicles, she said. The automaker plans to introduce a new battery-only electric commercial van in 2010 followed by a new all-electric small car in 2011. The electric car is expected to travel about 100 miles on a charge.

Drivers who want longer range can buy a hybrid or plug-in hybrid where gasoline power pushes the wheels much of the time. Fuel economy for a plug-in hybrid, according to Ford, would be about 120 miles per gallon.

Ford has said it would introduce several "next-generation" hybrids, including a plug-in, by 2012. "Next-generation" hybrids will have more advanced battery technology than today's hybrids, Ford said, allowing for more efficient performance and less reliance on the gas engine.

Plug-in hybrids will operate like today's hybrid vehicles - with both gasoline combustion and electricity driving the wheels - but they will be able to take in additional electric power by plugging into an outlet, which allows for such extremely high fuel economy

Electric plan

Ford experimented with its own prototype extended-range electric vehicle, like the Volt. Ford's was called the Edge with HySeries drive. It used a hydrogen fuel cell instead of a gas engine to generate extra power, but the principal was essentially the same.

But to provide acceptable performance once plug-in power is depleted, Ford engineers believe a gas engine would have to be too large to provide the kind of long-range fuel economy customers want, Samardzich said.

The alternative, she said, would be to use an engine so small that performance would be compromised.

Tony Posawatz, vehicle line director for Chevy's Volt program, disagreed with Samardzich. He insisted that the Volt will perform fine even when electric power was being generated by the car's fuel-efficient 1.4-liter engine.

"The only minor issue is in an extreme elevation," he said, "somewhere in Colorado, up a steep grade."

Posawatz called that a "less than 1% of the time issue" and said it was comparable to what drivers would feel with any small-engined car.

The Volt will by driven by pure electric power and will be able to travel up to 40 miles on plug-in power alone before needing to generate electricity on board. Chrysler has also said it is planning to have a line of such vehicles beginning next year.

Because 40 miles is farther than most Americans drive on the average day, GM and Chrysler boast that their vehicles could potentially go weeks needing little gasoline at all - if any.

Also, by starting with an extended range-electric vehicle, GM is maintaining maximum flexibility to follow where the market leads, Posawatz said. A vehicle like the Volt can easily be sold as a pure-electric vehicle by simply taking out the engine."

"It's much harder to go the other way," he said.

A conservative approach

Ford's plan for a purely plug-in electric vehicle by 2011, followed by a plug-in hybrid in 2012, would put it behind the plans of GM and Chrysler. Those carmakers, as well as Japan-based Toyota and Nissan, have already announced plans to have plug-in electric vehicles on the market as early as next year.

"Ford, I think, is playing a bit of a card game," said James Bell, editor of the automotive Web site Intellichoice.com.

Ford is betting that gas prices probably won't rise sharply in the next few years, Bell surmised. In the near term, the carmakers' so-called EcoBoost engines - turbocharged engines with highly sophisticated fuel injection systems - will provide the greater fuel economy Americans want as gas prices rise gradually.

"If gas prices go down, Ford's going to look like the cat with the canary in its mouth," Bell said.

Ford also simply tends to be more conservative, by nature, than GM, said Michele Krebs, a columnist for Edmunds.com's AutoObserver.com Web site.

All of these plans are driven by future, stricter federal fuel economy standards, not by natural consumer demands, she said. Despite a lot of media buzz around electric vehicles, consumers would ordinarily only buy them when the price and capabilities genuinely met their needs.

"We're moving into that era when it's going to be legislated, so consumers will have to get on board," she said.